(a) Field of the Invention
The present disclosure is directed to a display device and a manufacturing method thereof.
(b) Description of the Related Art
A flat panel display such as a liquid crystal display and an organic light emitting device includes several pairs of field generating electrodes and electro-optical active layers interposed therebetween. The liquid crystal display includes a liquid crystal layer as an electro-optical active layer, and the organic light emitting device includes an organic emission layer as the electro-optical active layer.
One electrode of a pair of field generating electrodes, i.e., a pixel electrode, is commonly connected to a switching element for transmitting electrical signals to the pixel electrode, and the electro-optical active layer converts the electrical signals to optical signals to display an image. In this case, the switching element is controlled by a gate line for transmitting gate signals and a data line for transmitting signals to be applied to the pixel electrode.
Additionally, this display device includes a gate driver applying gate-on voltages to the gate line and a data driver applying image signals to the data line. The gate driver and the data driver have a plurality of switching elements, which control signals transmitted from a signal controller.
An active matrix type of organic light emitting device includes a plurality of pixels, each including a switching transistor, a driving transistor, and a storage capacitor as well as an anode, a cathode, and a light emission layer, and the driving transistor receives a data voltage from the switching transistor and drives a current having a magnitude determined depending on the data voltage. The current from the driving transistor enters the light emission layer to cause light emission having intensity depending on the current.
In the active matrix type of organic light emitting device, characteristics of the switching thin film transistor and those of the driving thin film transistor may be different from each other. In detail, the switching thin film transistor may have a good on/off characteristic, and the driving thin film transistor may have a high mobility and stability for supplying sufficient current for driving the organic light emitting device.